Spring type toolholder



SPRING IYPE TOOLHOLDER Filed April 20, 4 1945 INYENTOR. 86

Patented Oct. 5, 1948 2,450,582 *y SPRING TYPE 'rooLHoLDER Lyof MartinCoyle, Babakin, Western Australia, Australiav Application April Z0,1945, Serial. No. 589,351 In Australia December 10, 1943 Section l,Public Law 690, August 8, 1946. Patent expires December 10, 1963 Thisinvention relates to improvements in spring type tool holders.

Although spring tool holders are comparatively effective forcutting-off, slotting, finishing, screwcutting and the like, yet theyare capable of considerable improvement, particularly in respect ofcutting off.

f These spring tool holders normallyfhave the springing action due to aslot in the holder between the main body :and the head in which thecutting tool is held. In one of these known types of tool holders theslot commences at the bottom edge of the holder, then runs approximatelystraight up, and is then curved in involute form to above and past thecentre line of the opening in the head in which the tool is held. Thespringing is controlled by a longitudinal bolt connecting the sprunghead to the body and capable of being tensionally adjusted by a nut.

In the tool holders of this type there has been a lack of lateralstability. That is to say, there has been a tendency for the head tospring sideways. Moreover, the means employed for holding the cuttershave been` such that if digging occurs, the result must be either severestrain or tool breakage, because the tool cannot free itself. Inaddition, there has been no possibility of substantially altering theheight of the cutting edge.

The tool holder comprising this invention overcomes the foregoingdisadvantages.

It consists of a holder in which the cutter is held in separatefrictionally held mountings, and these -mountings have an extension thatcontracts a Xed partl of the holder, thereby increasing lateralstability. Moreover, the height of the cutting edge oi the cutter canreadily be altered due to the mounting supporting it being frictionallyheld and therefore adjustable in the head.

Further, the tool holder will accommodate various mountings adapted totake a Variety of shapes and sizes of cutters in either the right orleft-hand position.

The invention will vreadily be understood by reference to theaccompanying drawings. In these- Figure 1 is a side elevation of thetool holder in which the ttings for holding the cutter have beenomitted:

Fig. 2 is a modified form oi tool holder such as may be used when it isdesired to have a low,

centered tool:

Fig. 3 is a front elevation of a side cheek being part of the means forholding the cutter:

4 claims. (c1. 25J-91.5)

2 Fig. l is a similar view of a holding bolt used in conjunction withthe cheek illustrated in the previous iigure:

Fig. 5 is a side elevation of the cheek illustrated in Fig. 3:

Fig. 6 is a front elevation of a modiiied iorm 1 of cheek for holdingthe cutter used, and

Fig. 'l is a front elevation ofanother modification for holding thecutter. y

As shown in the drawings, the tool holder Ill roughly conforms toconventional proportions though the head end is somewhat deeper than isusual. There is acurved slot or cut li whichk commences near the frontof the working end of thetool and extends in somewhat semi-circular formto the top past the centre line of where the tool mountings aresupported. Therefore the head lies closely yoked within the two prongsl2 yand I3 of the holder` body. A longitudinal bolt M passes through thetool so that, by anadjusting nut I5 spring tension may be varied todiierent requirements, for example to take up chatter and to act as astabiliser so that the head will not become dislodged through shock ofrebound or heavy spannering. The cutter is not mounted directly in thetool holder butin separate detachable and interchangeable mountings.

To accommodate these components or mountings,

the sprung head of the tool holder, which is in vertical alignment withthe unsprung prongs, is provided with an opening It transversely throughit.

One iormof mounting adapted `to take or hold the cutter is thatillustrated in Figs. 3, 4 and 5.

. This comprises a side cheek I1 that has a shank I8 passing through theopening I5 in the holder and has a nut I9 screwing on the end of theshank and adapted to engage against the far side of the head of theholder. Through the cheek and the shank there is an opening that`accommodates a holding bolt 26 having an enlarged and cut-awaycountersunk head 2i and a nut 22 screwed on to the shank at the far sideagainst the shank i8. The cutter is held in the recess 23 formed in thecheek I1 by the pressure of the countersunk head 2| of the holding bolt20.

A further form of mounting for holding the cutter is that illustrated inFig. 6. This also has the side cheek I1, shank I8 and bolt i9. It,however, has a square or rectangular opening Z4 in the cheek and thecutter is held in position by means of a set screw 25 passing into thecheek downwards from the top.

A still further mounting is that illustrated in Fig. 7. In this form,the cheek l1 is provided with 3 an opening through which passes awedge-type head 27 with a holding bolt 26 held in position by the nut I9screwed on in the usual way.

It will be noted that in each case the cutter mountings are madefrictionally to engage the sprung head l l to the required extent,whilst the lower portion of the side cheek I1 contacts the lowerunsprung prong I3 of the body so as to prevent lateral deflection. As aresult cf the way it is mounted, the cutter can free itself withoutbreakage in the case of digging in or seizure through choking. It isalso readily adjustable for height without disturbing the holder.

The modified form of holder illustrated in Fig. 2 is a form that will besuitable when it is desired to have -a low centred tool. In this case,the opening |6 can be made lower because there is no head of the bolt i4to be fouled. In this case, an inset 28 is tapped to act as a nut forthe bolt I 4. In this and other forms of the invention also there may bea slot 29 at the far end of the holder so as to give additionalresiliency in the vicinity of the nut l5.

I claim:

1. A tool holder of the spring type comprising in combination a headportion formed therewith and having an opening therein, said holderhaving a curved slot formed therein that commences near the forward endof said head portion and extending in substantially a semi-circularforni to above and forward of the opening formed therein whereby saidhead portion will be resiliently connected to said holder, a mountingextending through the opening Within said head portion and frictionallyheld to the latter, a cheek for holding the cutting tool forming a partof said mounting and extended so as to engage against a iixed part ofsaid holder as Well as said resiliently connected head portion and meansfor holding the cutting tool in said frictionally held mounting.

2. A tool holder of thespring type comprising in combination a headportion formed therewith and having an opening therein, said holderhaving a curved slot formed therein that commences near the forward endof said head portion and extending in substantially a semi-circular formto above and forward of the opening formed therein whereby said headportion will be resiliently connected to. said holder, a mounting, ashank formed with said mounting and extending through the opening withinsaid head portion, a

nut engaging said shank for frictionally retaining said mounting to saidhead portion, a cheek forming part of said mounting and extended so asto engage against a iixed part of said holder as well as against saidresiliently connected head portion and means for holding a cutting toolwithin said frictionally held mounting,

3. A tool holder of the spring type comprising in combination a headportion formed therewith and having an opening therein, said holderhaving a curved slot formed therein that commences near the forward endof said head portion and extending in substantially a semi-circular formto above and forward of the opening formed therein whereby said headportion will be resiliently connected to said holder, a mounting, ashank extending through the opening within said head portion, meansengageable with said shank for frictionally retaining said mounting uponsaid head portion, a cheek formed with said mounting, a threaded shankconnected to said cheek and extending through said shank formed withsaid mounting, a nut engageable with said threaded shank forfrictionally holding said cheek upon said mounting and an enlarged andcountersunk head formed with said threaded shank for retaining thecutter tool in position within said cheek. si. A tool holder of thespring type comprising in combination a head portion formed therewithand having an opening therein, said holder having a curved slot formedtherein that commences near the forward end of said head portion andextending in substantially a semi-circular form io above and forward ofthe opening formed therein whereby said head portion will be resilientiyconnected to said holder, a mounting, a holiow shank formed with saidmounting and extending through the opening within said head portion,means engageable With said hollow shank for frictionally retaining saidmounting upon said head portion,'a cheek forming a part of saidmounting, said cheek having extending portions engageable with said`holder and head portion, a bolt extending through said cheek and hollowshank of said mounting, a Wedge-shaped head formed with said bolt andmeans engageable with said bolt for frictionally retaining said cheekinto engagement with said head portion as well as retaining the cuttingtool within said cheek.

LYOF MARTIN COYLE.

REFERENCES CITED The following references are of record in the ile ofthis patent:

UNITED STATES PATENTS Number Name Date 801,256 Moore Oct. l0, 1905872,760 Schulz Dec, 3, 1907 932,576 Ramsey Aug 31, 1909 1,214,225`Schillberg June 30, 1917 1,416,832 Johansson May 23, 1922 1,422,491Stahl July 11, 1922 FOREIGN PATENTS Number Country Date 524,930 FranceSept. 13, 1921

